Composition for use in raised printing and method of preparation



Patented Feb. 10, 19 42 COMPOSITION FOR USE IN RAISED PRINT- ING AND METHOD OF PREPARATION A. De Vere Harriett, Racine, Wis.

No Drawing.

Application March 26, 1938,

Serial No. 198,270

14 Claims.

This invention relates to improvements in a process of raised printing and to an improved compound for use in the practice of that process, and the purpose of the invention is to provide means for causing ordinary flat printing, etchings and the like, to assume the formand appearance of embossed printing or engraving.

Various attempts have heretofore been made to produce raised printing by the use of compounds, usually consisting largely of shellac, which have been dusted onto the wet printed surfaces, after which the powder on the unprinted areas has been removed and then heat has been applied to cause the printing owder to fuse and unite with the ink and the paper to give an embossed efiect. These prior methods have generally been unsatisfactory because the raised printing has not been attractive and uniform in appearance and for the further, and perhaps more serious, reason that the material giving the raised efiect has clipped and flaked off when the printed sheets have been folded or rubbed together.

The. principal object of the present invention is to provide an improved compound which may be applied in the form of a powder to the inked surfaces and which will have a uniform and attractive appearance and not chip or peel off after being fixed in place by the application of heat. A further object. is to provide an improved process involving the use of a printing powder which will give a permanent raised effect and having a uniform attractive appearance with any desired gloss or finish. Still another object is to provide an improved method of forming a compound intended for use in raised printing processes and capable of forming raised letters or designs wh ch are tough and flexible and incapable of being removed by ordinary usage. These and other objects and advantages of the invention will appear more fully hereinafter.

The nature of the invention and the manner of its use will be understood from the following specification in which several forms of the improved compound are described together with the method of forming them and the process of using them.

In general, the improved printing powder of the present invention comprises a resin, ca cium carbonate, or its equivalent, and zinc stearate. or other suitable flattening agent, which are ground up, mixed together while heat is applied, and

As the sheets bearing After being except those parts which have been inked which carry a layer of the powder adhering to the ink. The sheets are then carried by the belt beneath a hood which forms a heat chamber over the sheets and in which a sufiicient degree of heat is maintained to fuse the printing powder and cause it to unite with the underlying ink and the paper to form a permanent bond therewith. The application of the heat also causes the powder to assume the desired raised form with a uniform surface texture and appearance. After passing from-this hood, the sheets are subjected to the action of a blower or other device for cooling the raised printed matter carried by the sheets and the sheets may then be stacked without danger of any parts of the printed matter rubbing ofiz'.

The resin used in forming the printing powder is preferably in the form of what may be termed a base resin comprising a high quality resin to which are added ethyl cellulose and a liquid methyl ester, preferably that compound known in the trade as Hercolyn having the formula C19H31COOCH3. The ethyl cellulose is preferably one having a low viscosity and it is employed to give toughness and flexibility to the final compound. The Hercolyn is used to regulate the melting point of the compound and to increase its flexibility and it also serves as a plasticizer, in addition to causing penetration of the paper and preventing the undue hardening of the compound. Although Hercolyn is preferably used as the-plasticizer and regulating agent, other plasticizers may be used, such as dibutyl phthalate; or those compounds known in the tradeas Aroclors, particularly those Aroclors bearing numbers 1248 and 1254. The base resin having these ingredients is preferably formed pr'elimlnary to the manufacture of the complete printing compound or powder and, in forming the base resin, the ingredients are preferably combined in the following proportions:

, J Pounds Resin '70 Ethyl cellulose 17 /2 Hercolyn 17 /2 patible, it is meant that the resin is compatible with ethyl cellulose in the proportions in which these ingredients are used. This melting point may be varied, but with the harder resins it is desirable to increase the amount of Hercolyn or other plasticizer employed. In forming the base resin, the supply resin is melted in a kettle equipped with an agitator, the temperature being maintained at about 300 Fahrenheit until the resin is completely melted. The agitator is then started in operation and the ethyl cellulose is slowly added while the mixing continues. The Hercolyn is then gradually added while continuing the agitation of the mixture and when all three ingredients have been completely mixed, the heat is increased to run the temperature to about 450 F. at which point the mixture is held for about fifteen minutes. The hot mixture is then run into pans for cooling. The base resin thus formed can be employed in the manufacture of any of the printing powders hereinafter described.

The printing powders of the present invention are capable of producing a flat finish on the final raised printing product, or any desired degree of gloss or shine. The compounds for producing two degrees of gloss termed satin gloss and semigloss and also for producing a fiat finish are herein described, together with the methods of forming them.

Satin gloss compound stearate or other suitable flattening agent, such as aluminum stearate or carnauba. The base resin, Surfex and zinc stearate are preferably combined in the following proportions:

, Pounds Base resin 173% Surfex 14 /2 Zinc stear f 21% In forming the satin gloss compound, the base resin is first placed in a vessel having an agitator, such as a single-armed dough mixer, and

a heat is applied until the base resin has been melted into a heavy paste. The Surfex is then added to the molten base resin while agitating the mixture. The Surfex is preferably sifted in slowly to avoid lumping and when all of the Surfex has been added the zinc stearate is similarly added to the mixture in a gradual manner while continuing the agitation. The temperature should be kept as low as possible while maintaining the mixture in a sufficiently liquid state to permit agitation and mixing, as it has been found that the Surfex will tend to separate if too much heat is applied. After all of these ingredients have been mixed together, the heat is reduced and the mixing is continued until the paste is very heavy, whereupon it is poured into trays to cool. It is desirable to pour the liquid paste into the trays very slowly in order to effect a partial cooling thereof during the pouring process, thereby avoiding separation of the ingredients. The mixture will then harden to form the completed compound which is subsequently ground up to form a powder for use in the printing process referred to above. I After being ground, the powder is preferably graded by sifting, in order to produce materials of variOusdegrees of finetoughness of the mixture while at the same time preventing brittleness. The resin performs'the function of givingbody to the mixture and of ness for various grades of printing. The Surfex' causing adhesion to the overlying ink and paper. The zinc stearate, or its equivalent, acts as a heat conductor and tends to decrease the melting point of th resin and also acts as a flattening agent to control the lustre of the finished product. By increasing the amount of zinc stearate, the gloss of the finished product may be diminished and, in order to retain the desired toughness and flexibility in the product a the amount of zinc stearate is increased, the amount of Surfex employed should also be increased.

Semigloss compound One example of the effect of increasing the amount of Surfex and zinc stearate in the compound is illustrated by that particular compound which is termed "semigloss in which the foregoing ingredients are preferably combined in the following proportions:

Pounds Base resin 131 Surfex 27 Zinc stearate 51%,

These ingredients are mixed together according to the procedure described above in connection with the satin gloss compound and the resulting powder gives a raised printing efiect accompanied by a diminished shine or finish as compared with that produced by the compound previously described.

Flat finish compound If it be desired to product raised letters or printed matter having a flat finish, the amount of the base resin is further reduced and the amounts of the other two ingredients are further increased, preferably according to the following table of proportions:

Pounds Base res -l- Surfex- 41% Zinc stearate 58 These ingredients are mixed together in the manner previously described in connection with the satin gloss compound, and thev resulting product is powdered and used in the same manner but the resulting raised letters will be substantially free of shine or finish.

Lustre white compound tions: H

Satin gloss compound poui1ds 21% Titanium dioxide do.. 13% Zinc oxide dol. 4 Ultramarine blue ounce V The titanium dioxide is added to give the white color, the zinc oxide serves to increase the whiteness and hardness of the mixture, and the ultramar'ine blue has a further whitening efiect. -If desired, one of these white coloring agents may be employed alone in the proportions which-are provided for all three of them, but it has been found that the best results are obtained by mixthe mixture at the conclusion of the original process of manufacture of the satin gloss compound, using the proportions indicated by the foregoing table.

Eggshell white compound If it be desired to produce a less shiny finish in the white-colored printed matter, the semigloss compound may be used as the base of the colored mixture. In that event, the ingredients are preferably combined in-the following proportions:

semigloss compound pounds 25 Titanium dioxide do 13 Zinc oxidedo 4% Ultramarine blue ounce As in the case of the lustre white compound, de-

- scribed above, any one of the white coloring agents may be employed in the proportions which are prescribed for all three of them, but the best results are obtained by using all three ofthem in the proportions indicated. The mixture is formed by adding the ingredients to the semigloss compound in the manner described above for the lustre white compound.

bull white compound If itbe desired to give a dull white finish to the resulting printed matter, the fiat finish compound is employed as the base of the mixture and, in that event, the ingredients are preferably combined in the following proportions:

Flat finish compound pounds 27 Titanium dioxide do 10 Zinc oxidedo 3 /2 Ultramarine blue ounce /z These ingredients are put together in the manner described above in connection with the formation of the lustre white compound and the three white coloring agents are preferably employed together, although one of them may be employed alone.

- Any. other suitable color may be given to the printing powder by adding a small quantity of the desired coloring agent to any one of the primary printing powders, such as the satin gloss compound, the semigloss compound or the flat finish compound.

All of these printing compounds, after being hardened by cooling, are ground up into the form of a powder and are then employed in the raised printing process heretofore described by dusting them onto the printedsurfaces. Although, some latitude is permissible in the substitution of equivalents for the ingredients which have been prescribed as being preferably employed, while still retaining the advantage of a flexible, durable and attractive printing effect, it has been found in practice that when the particular ingredients known as Hercolyn and Surfex are used, the results are very much better than those obtained when using the substitutes which have been mentioned as equivalents therefor.

Although certain examples of the improved compositionof matter for use as a printing powder have been described in detail by way of illustration together with the methods of producing them and the manner of their use, it will be understood thatall of these features of the invention may be modified in various ways without departing from the scope of the appended claims.

I claim:

1. A printing powder comprising resin which is compatible with ethyl cellulose, ethyl cellulose and a methyl ester of abieticiacid.

2. A printing powder comprising resin which is compatible with ethyl cellulose, ethyl cellulose, a methyl ester of abietic acid and calcium carbonate.

3. A printing powder comprising resin which is compatible with ethyl cellulose, ethyl cellulose, a methyl ester of abietic acid,-calcium carbonate and zinc stearate.

4. A printing powder comprising resin which is compatible with ethyl cellulose, ethyl cellulose, a methyl ester of abietic acid, calcium carbonate, and coloring matter.

5. A printing powder comprising resin which is compatible with ethyl cellulose, ethyl cellulose, a methyl ester of abietic acid, calcium carbonate,

zinc stearate, and titanium dioxide.

6. A printing powder comprising resin which is compatible with ethyl cellulose, ethyl cellulose, a

compatible with ethyl cellulose, ethyl cellulose, a

methyl ester of abietic acid, calcium carbonate, zinc stearate, titanium dioxide, zinc oxide, and

- ultramarine blue.

9. A printing powder comprising a base resin, composed of resin which is compatible with ethyl cellulose, ethyl cellulose and a methyl ester of abietic acid combined in the proportions of 70 pounds resin, 17 pounds ethyl cellulose and 17 pounds methyl ester of abietic acid.

10. A printing powder comprising a base resin, composed of resin which is compatible with ethyl cellulose, ethyl cellulose and a methyl ester of abietic acid, having added thereto calcium carbonate and zinc stearate, said ingredients being combined in the proportions of 173% pounds of base resin, 14 pounds calcium carbonate and 21% pounds zinc stearate.

11. A printing powder comprising a base resin, composed of resin which is compatible with ethyl cellulose, ethyl cellulose and a methyl ester of abietic acid, having added thereto calcium carbonate and zinc stearate, said ingredients being combined in the proportions of 131 pounds of base resin, 27% pounds calcium carbonate and 21% pounds zinc stearate.

12. A printing powder comprising a base resin, composed of resin which is compatible with ethyl cellulose, ethyl cellulose and a inethyl ester of abietic acid, having added thereto calcium carwhich is compatible with ethyl cellulose to the melting point and then adding thereto in succession ethyl cellulose and a methyl ester of abietic acid while agitating the mixture, maintaining the mixture in a plastic state and adding thereto powdered calcium carbonate, then adding to the mixture a. quantity of zinc stearate, continuing the agitation while allowing the mixture to cool, then pouring the mixture into trays to harden, and then grinding up the hardened product to form a powder.

A. DE VERE HARNETT. 

